what does "merge" local contacts mean when turning on iCloud contacts?

Hello JohnnyMathis,

Welcome to Apple Support Communities!

If we understand your post correctly, you want to know what it means to merge contacts when turning on iCloud. We're here to provide that information to you.

To merge contacts means you're merging the contacts that are currently stored on the phone with the contacts that are stored in iCloud.

More information can be found in this article: Set up and use iCloud Contacts

Let us know if you have any questions.

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Take care!